1. Technical Field
The present invention relates to frames of bicycles, and more particularly to a fibrous composite frame.
2. Description of Related Art
While most early bicycle frames made of aluminum alloy are structurally robust and heavy in weight, the modern bicycles are usually designed with frames made of carbon-fiber composite materials that is also tough yet much lighter than aluminum alloy, so as to answer to the trend of light weight.
For using a carbon-fiber composite material to make a bicycle frame, the carbon-fiber composite material is shaped by wrapping an inflatable member, and after the bicycle frame is formed, the inflatable member is deflated and withdrawn from the formed bicycle frame. Such a manufacturing process is complicated and inconvenient. Especially, a bicycle frame is constructed by plural tubes, and it is more than difficult to use the foregoing manufacturing process to produce tubes linked as a unitary member. Furthermore, since the inflatable member is somehow soft even when fully inflated, it is almost impossible that the carbon-fiber composite material closely wraps the inflatable member. Moreover, the formed carbon-fiber composite bicycle frame is a tubular, hollow structure, so in the event that the material is not sufficiently thick, the frame tends to break. On the other hand, if the thickness of the material is increased, the desire for light weight would be sacrificed.